B. Silliman on Illuminating Oil from California Tar. 245 
pressure was used or not; a certain loss, all falling upon the 
lighter portions, was found to result from leakage of the appa- 
ratus under pressure, which in the larger way of operating com- 
mercially could be avoided. 
No paraftine could be detected by refrigerating the heavy oils 
obtained in these distillations in a mixture of salt and ice. It 
is no doubt the absence of this body from the series of products 
obtained from the California oils generally, that accounts for the 
illuminating oil burning well at a density considerably below 
the commercial standard for oil obtained from Pennsylvania pe- 
troleum—a difference enhanced also by the absence of any con- 
siderable quantity of light naphtha. The lubricating oils of 
this series, likewise free from paraffine, retain on this account 
their fluidity at low temperatures. 
The light oils obtained in this series of experiments corres- 
pond respectively to 12°96, 14°56 — 18-96 per centum of the 
crude oil. The total commercial products are about 60 per cent 
of the crude body, which likewise os sufficient dig to supply 
the fuel required in the distillatio 
In the large way, by returning as lightest oils to the heav- 
ier portions in the successive distillations and employing Mr. 
Young’s method by pressure, it is probable the product of light 
or illuminating oils may be raised in these very heavy natural 
products to 80 per cent. 
It is evident from these experiments that heavy hydrocarbon 
oils containing no naphtha are convertible into oils of the naph- 
tha series under the action of heat by molecular transformations, 
the excess of carbon being left behind as coke; each successive 
distillation eliminating a new but always a diminished portion of 
carbon 
Tam indebted to Mr. A. J. Corning, formerly assistant to Mr. 
Warren, for conducting this research under my direction; and 
to Messrs. Downer and Merrill, of the kerosene works in South 
ton, I am under many obligations for the permission to em- 
ploy their operative laboratory in conducting this research. As 
before stated, the research had chiefly a technical object, the 
’ ints of see tied interest being subordinate in a great degree. 
or the crude material operated on I am indebted to the Califor- 
nia Petroleum Company, from whose estate it was derived. 
g 
a “Pico Spine.” 
Barbara county, California. This sa mple, as well as rs sul 
UR. Sc1.—Seconp SERIES, Ven. XLII, No. 128.—Manon, iser. 
32 
